To enable JFFS you will need a router with at least 4MB flash, a build that supports JFFS such as the Mini build which is the smallest build to support JFFS thus leaving the most space for the JFFS partition, and your build must leave at least 324KB of flash free for the JFFS file system structure which will not be usable space. v24 pre-SP2 Standard builds no longer leave enough space for JFFS on 4MB devices so use the Mini build or one of Eko's specialty builds.

Very old versions of some Linksys routers (no longer manufactured for many years) contained 8MB of Flash and 32MB of RAM, many DD-WRT-capable devices today contain 4MB of Flash memory; a few models from certain manufacturers contain more flash (La Fonera, ASUS WL-500GP), some contain less (2MB). See Supported Devices.

Note that DD-WRT v24sp1 VPN builds have the JFFS feature removed, presumably due to conflicts that Brainslayer found between JFFS and bandwidth monitoring. See this thread for more information. Users interested in v24sp2 can opt:

As of October 7th, 2009, consider the following or you may BRICK your WL500W router:

Brainslayers mega flash size - 7.33MB

Eko's Big Flash size - 5.9MB

Now, the error only occurs when JFFS2 is enabled and the router reboots, so you are safe if you DONT enable JFFS2.

Total available JFFS2 size for BS's build is 640KB which overwhelms the kernel and causes a panic. Even using a storage device with the command mount -o bind /mnt/jffs /jffs will still cause a kernel panic.

Eko's JFFS2 partition size is 1640KB+, allowing much more room.

I tested this on BS's 12996,12874 and 12533 builds and partially bricked my router several times. (A simple power disconnect for 30 secs will allow it to recover)

Eko's build however works flawlessly AND provides the SAME features (except for connection warning) as BS's.

One thing I am still unsure of is why this particular model Asus router is subject to this bug, but in the mean time, I suggest using Eko's Big build until the dev's can work it out..

The steps to enable JFFS through the router web page are very specific. To avoid having to reset and reprogram your router, it's smart to make a backup here of your settings. If you follow these steps exactly, it should not lock up.

On the router web page click on Administration.

Scroll down until you see JFFS2 Support section.

Click Enable JFFS.

Click Save.

Wait couple seconds, then click Apply.

Wait again. Go back to the Enable JFFS section, and enable Clean JFFS.

Do not click "Save". Click Apply instead.

The router formats the available space.

Wait till you get the web-GUI back, then disable "Clean JFFS" again.

Click "Save".

It may be wise to Reboot the router, just to make sure

If you don't see the Enable JFFS option on your Administration page, it is likely because your router has insufficient flash memory to hold both DD-WRT and a JFFS partition. If you have a 4MB router, you may be able to work around this by using the mini version of DD-WRT

A user comments: I tried the following commands under La Fonera firmware v24 RC4 and corrupted all my settings. I had to recover my unit with the procedures on La Fonera flashing page. I am not sure if this is a bug or these commands are not suited for La Fonera. Please try to use the web interface above. It works for me.

This method uses 2 scripts: The first will be started from /tmp/smbshare & mount the samba share under /jffs and start the other script. The second will be started from /jffs and unmount /tmp/sambashare.

#!/bin/sh
#wait a sec, just to be sure the smb startup script has quit
sleep 1
#unmount the smbshare, its identical to /jffs now anyway :)
umount /tmp/smbshare
#to enable ipkg, we fake JFFS enabled.
#since theres no commit, this wont actually create a /jffs at Startup.
nvram set sys_enable_jffs2=1
#ready to do specific stuff, like starting services
#or other commands from /jffs

5. in the webinterface, enable CIFS with appropriate share/user/pass settings from step 2.

Enter "startup.smb.sh" as the script

6. Apply Changes
7. reboot

Now you should have the share configured in the web interface mounted at /jffs and should also be able to run 'ipkg' !

NOTE: If you are a Linux newbie, and you have problems with file permissions, look at this

Script files must be saved in UNIX format, not DOS. Windows editors that can do this are UltraEdit. EditPadPro and Crimson Editor, are free.